Caliper



Aug. 14, 1928. 1,680,566

G. PARKER GALIPER Filed Oct. 1, 1927 Fig.5.

ZTZUGIIZOI'. Zl/zmcasca a) I M gww'ay Patented Aug. 14, 1928.

1,680,566 UNITED STATES. PATENT OFFICE."

GORDON PARKER, OF COLORADO SPRINGS, COLORADO, ASSIGNCR, BY MESNE ASSIGN-MENTS, TO THE PEOPLE OF THE UNITED STATES.

CALIBER.

Application filed October 1, 1927. Serial No. 223,400.

(GRANTED UNDER THE PROV'I SISNS 11-1 THE ACT This application is madeunder the act of March 3, 1883, chapter 143 (22 Stat. 625) and theinvention herein described and claimed may be used by the Government of6 the United States or any of its ofiicers or employees in theprosecution of workfor the Government, or by any citizen of the UnitedStates, without payment to me of any royalty thereon.

In the accompanying drawing Fig. 1 is a plan view of the caliper; F ig.2 is a detail of the sleeve member as positioned on a section of one ofthe arms of the caliper; and Fig. 3 is a plan view of the cross bar withcalibrations thereon.

Referring to the drawings, it will be seen that the caliper consists ofarms 1 and 2, pivoted at one end by bolt 8 so located that it is in linewith the inside edges 1 and 2,

of said arms. A cross member 3 with calibrations 4 is pivoted at one end3 to arm 2 by bolt 5 and the other end 3 of said cross member passesthrough and is adapted to slide in sleeve 6, preferably fashioned in theform of a hollow square, held in position on arm 1 by means of a.boltlike extension 7 through said arm and nut 9 and washer 10. The bolt5 and sleeve 6 are positioned on arms 1 and 2 an equal distance frompivot 8. The inside edges 1 and 2f of said arms between pivot 8 and thecross member 3, together with the outside edge 3 of said cross memberform an isosceles triangle, the base of the triangle being the outeredge of the cross member. The altitude of the triangle varies as thecompass-like arms 1 and 2 are opened.

In operation the caliper is opened and placed against the tree or log atright angles so that one arm of the calipers and the cross member bothtouch the tree. The other arm of the caliper is then moved up until ittouches the tree snugly. The tree is thus enclosed between both arms ofthe caliper and the cross-member and touches allthree. The cross-memberbears a. series of graduations or calibrations which begin at thepivoted end of the'cross-member and extend out towards its free end. Thecalibrations are so arranged as to give the diameter of the ed for thisdevice that it OF MARCH 3, 1883, 22 STAT. LJ, 625.)

tree or log being measured by reading the graduation at'the point wherethe inside edge, of arm #1 intersects the cross-member. The graduationsfor convenience in reading are placed on the side 01": the crossmemberwhich faces the operator.

The cross-member is customarily graduated to give diameters in inchesbut can as easily be calibrated to give readings in other units ofmeasurement if desired. The size of the complete instrument will varyaccording to the average size of the trees and logs to be measured. Fortimber up to 36 in diameter calipers with arms 32" long and across-member 22 in length located 18 from the central pivot issatisfactory. When not in use the free end of sleeve by opening the armswide enough. The cross-member may then be folded down against the closedarms i'naking an extremely compact instrument.

The entire caliper can be. constructed of metal if desired. In order tosecure lightness the arms and cross-member will ordinarily be fashionedof wood with sleeve and pivot fastenings of metal. It is claimis simple,very easily and quickly operated and gives accurate results. It isinexpensive to construct, does not get out of order and is very easilytransported.

I claim:

I The herein described. caliper comprising.

twoarnis pivoted at one of their ends, a cross member with calibrationsthereon pivoted to one arm intermediate its length, means pivotally andslidably connecting said member to the other arm intermediate itslength, the pivot points for said cross member be lng equidistant fromthe pivot point for the arms so as to form indifferent adjustment-s anisosceles triangle, whereby when the caliper is placed at right anglesto the object to be measured and the said arms and said cross member arein contact with said object the diameter of said object will beindicated by said connecting means on the calibrations on said crossmember.

GORDON PARKER.

the cross-member can be slipped out of its

